Institute of Organic Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany; Department of Chemistry, University of Pretoria, Pretoria 0001, South Africa; Faculté des Sciences et Sciences Appliquées, Université Officielle de Bukavu, B.P. 570 Bukavu, Democratic Republic of the Congo.
Institute of Organic Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany; Faculté des Sciences, Université de Kinshasa, B.P. 202, Kinshasa, XI, Democratic Republic of the Congo.
Fitoterapia. 2018 Oct;130:6-16. doi: 10.1016/j.fitote.2018.07.017. Epub 2018 Jul 27.
Four new naphthylisoquinoline alkaloids, the 5,8'-coupled ancistroyafungines A-C (1-3) and the 5,1'-linked ancistroyafungine D (4), have been isolated from the stem bark of an as yet unidentified Ancistrocladus (Ancistrocladaceae) liana recently discovered near the village Yafunga, in the North-Central region of the Democratic Republic of the Congo. Likewise obtained were eleven analogs previously identified in related African and Asian Ancistrocladus species, exhibiting five different coupling types, viz., 5,8', 5,1', 7,1', N,6', and N,8'. All of the alkaloids are S-configured at C-3 and possess an oxygen function at C-6 in the isoquinoline portion, and, thus, belong to the subclass of "Ancistrocladaceae-type" alkaloids. This finding is geo- and chemotaxonomically remarkable, since - apart from one other Ancistrocladus species from the Central Congo Basin - only Southeast Asian and East African Ancistrocladaceae are known to exclusively produce naphthylisoquinolines with these structural features. Moreover, the alkaloid pattern of this Congolese liana clearly demarcates this plant from all other Ancistrocladus taxa that have so far been botanically described, which suggests that it might represent a new species or subspecies. The new ancistroyafungines display strong preferential cytotoxic activities towards human PANC-1 pancreatic cancer cells in nutrient-deprived medium, without showing toxicity in normal, nutrient-rich conditions.
四种新的萘基异喹啉生物碱，即 5,8'-偶联Ancistroyafungine A-C（1-3）和 5,1'-连接的Ancistroyafungine D（4），已从一种尚未鉴定的Ancistrocladus（Ancistrocladaceae）藤本植物的茎皮中分离出来，这种植物最近在刚果民主共和国中北部的 Yafunga 村附近被发现。同样获得的还有以前在相关的非洲和亚洲Ancistrocladus 物种中鉴定出的十一种类似物，它们表现出五种不同的偶联类型，即 5,8'，5,1'，7,1'，N,6'和 N,8'。所有生物碱在异喹啉部分的 C-3 位均为 S-构型，并且在 C-6 位具有氧官能团，因此属于“Ancistrocladaceae 型”生物碱的亚类。这一发现具有地理和化学分类学意义，因为除了来自刚果中部盆地的另一种 Ancistrocladus 物种外，仅东南亚和东非的 Ancistrocladaceae 被认为专门产生具有这些结构特征的萘基异喹啉。此外，这种刚果藤蔓的生物碱模式清楚地区分了该植物与迄今为止在植物学上描述的所有其他 Ancistrocladus 分类群，这表明它可能代表一个新的物种或亚种。新的Ancistroyafungines 在营养缺乏的培养基中对人 PANC-1 胰腺癌细胞显示出强烈的选择性细胞毒性，而在正常、营养丰富的条件下没有显示出毒性。
